Method of tobacco sucker inhibition

ABSTRACT

The inhibition of the growth of tobacco plant suckers by the application to the tobacco plant of benzylthiolcarbamate having the formula,   WHEREIN R1 and R2 are selected from the group consisting of acetyl, cyclohexyl, and C1-6 alkyl group; X and Y are selected from the group consisting of nitro, acetyl, amino, C1-3 alkyl, C1-3 alkoxyl, and halogen; and M AND N ARE 0 OR 1.

United States Patent [191 Fujikawa et al.

[ 51 May 13,1975

[ METHOD OF TOBACCO SUCKER INHIBITION [75] Inventors: Kanichi Fujikawa; Ryohei Takahashi; Isao Yokomichi; Fumio Kimura; Takeo Kaji; Nobuyuki Sakashita, all of Kusatsu, Japan [73] Assignee: Ishihara Sangyo Kaisha Ltd., Japan [22] Filed: Mar. 12, 1973 [21] Appl. No.: 340,534

[30] Foreign Application Priority Data OTHER PUBLICATIONS lchiro et al., Chem. Abst., Vol. 76, (1972), 136878w. Klingman, Chem. Abst., Vol. 58, (1963), 28021 Primary Exanziner-Lewis Gotts Assistant ExaminerCatherine L. Mills Attorney, Agent, or Firm-Oblon, Fisher, Spivak, McClelland & Maier [57] ABSTRACT The inhibition of the growth of tobacco plant suckers by the application to the tobacco plant of benzylthiolcarbamate having the formula,

0 m 3- CH SCN (Y)n/ e? wherein R and R are selected from the group consisting of acetyl, cyclohexyl, and C alkyl group;

X and Y are selected from the group consisting of nitro, acetyl, amino, C, alkyl, C alkoxyl, and halogen; and

m and n are Oor 1.

5 Claims, No Drawings 1 METHOD OF TOBACCO SUCKER INHIBITION BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for inhibiting the growth of tobacco suckers. More particularly, it relates to a method for chemically treating tobacco plants to inhibit the growth of tobacco sucker.

2. Description of the Prior Art In the culturing of tobacco, sucker development causes a decrease in the effective yield of tobacco leaves and in the quality of the leaves. Thus, removal of the suckers from the plants is an indispensable operation. In the past, removal of the suckers by hand has been a laborious and time-consuming process. A need, therefore, exists for an effective means of chemically treating tobacco plants to inhibit the growth of tobacco suckers.

SUMMARY OF THE INVENTION wherein R and R and C alkyl groups, the acetyl group or the cyclohexyl group; X and Y are C alkyl groups, C alkoxy groups, the nitro group, the acetyl group, the amino group or a halogen atom; and m and n are or 1, to tobacco plants.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS I It is preferable in the method of this invention to apply a tobacco sucker inhibitory amount of N,N- dialkylbenzylthiolcarbamate having the formula,

phenylcarbamate, isopropyl N-(3-chlorophenyl) carbamate, isopropyl N-(3-methylphenyl) carbamate, and sec-butyl N-(3-methylphenyl) carbamate; or (b) a 2,6-dinitro-4-substituted aniline derivative such as N- sec-butyl-4-tert-butyl-2,6-dinitroaniline, N,N-di-npropyl-4-trifluoromethyl-2,6-dinitroaniline and N,N- di-n-propyl-4-methylsulfonyl-2,6-dinitroaniline to the tobacco plants.

In the benzylthiolcarbamates (l) and N,N- dialkylbenzylthiolcarbamates (2), suitable R R R and R groups include C alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secbutyl, tert-butyl, pentyl and hexyl, and suitable X and Y groups include C alkyl groups such as methyl, ethyl, n-propyl and isopropyl groups and C alkoxyl groups such as methoxy, ethoxy, n-propoxy and iso-propoxy groups.

Generally, the benzylthiolcarbamate or a composition thereof is applied in the form of a solution, an emulsion or a dispersion to tobacco plants in the top-- ping stage of growth. It is especially preferable to apply the composition to the stems and leaves near the suckers of the topped tobacco plants or the plants on which the flower buds have newly formed.

The benzylthiolcarbamates can be prepared by reactl. a benzylmercaptan having the formula ECH SH (Yl with a carbamoylhalide having the formula 0 ll A 1 CNR R wherein RI Z 1 CHSCN 2 8 2 (X) H128 (Y) with an amine having the formula HNR R CH2SCA1 wherein X, Y, m, n, R R and A are defined as above in the presence of an alkali; or 3. a benzylhalide having the formula CII A mm 2 1 with a thiolcarbamate having the formula wherein X, Y, m, n, R R and A are defined as above and A represents an alkali metal, the ammonium group or a lower alkyl ammonium group.

The concentrations of the active ingredients and the amount of active ingredient used for each tobacco plant are dependent upon the varieties of tobacco, growth conditions and methods of application of the composition. When a benzylthiolcarbamate is applied to the plants without an auxiliary active ingredient, the concentrations of the active ingredient in the composition range from 100-10,000 ppm, preferably 1,000- ,000 ppm.

When N,N-dialkylbenzylthiolcarbamate is applied to the tobacco plants with an alkyl N-phenylcarbamate or a 2,6-dinitro-4-substituted aniline derivative, the concentration of each compound in the composition is in the range of 50 4,000 ppm, preferably 500 3,000

The amounts of the aqueous composition applied to each tobacco plant is in the range of l 100 ml, preferably 100 ml, especially, 50 ml. The ratio of the active ingredient to the auxiliary active ingredient is not limited, and it is preferably in the range of 0.05 16, especially 0.1 6 parts by weight of alkyl-N- phenylcarbamate or a 2,6-dinitro-4-substituted aniline derivative per 1 part by weight of N,N-dialkylbenzylthiolcarbamate.

The compositions of this invention can be prepared by dispersing said active ingredient in water, or by admixing the active ingredient with an inert solid carrier such as talc, kaolin, bentonite, Zeeklite, starch or the like, or with an inert liquid carrier such as an alcohol, acetone, xylene, benzene, solvent naphtha, isophorone or the like. In addition, the compositions can contain a surfactant such as sodium alkylbenzenesulfonate, sodium higher alcohol sulfonate, polyoxyethylene alkylacryl ether, polyoxyethyleneglycol alkyl ether, calcium ligninesulfonate, polyvinylalcohol or the like in order to disperse the mixture in water.

When the tobacco plants are fully grown, the suckers of the plants begin to sprout. The growth of the suckers is promoted by a topping treatment. Usually, the sucker inhibitors are applied to the plants with the topping treatment. However, the sucker inhibitors can also be effectively applied to the plants during the growth of the suckers. If the active ingredient in the compositions of this invention is applied to the stems and leaves of the tobacco plants near the suckers, sprouting and growth of the suckers can be inhibited without chemical injury to the useful tobacco leaves. Thus, the application of the compositions is remarkably effective for the culture of tobacco.

Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.

The following examples show some of the typical formulations of this invention and the test results from the application of the compositions to tobacco plants. These results include the sucker inhibitory effects of the compositions and the extent of chemical injury to the plants.

EXAMPLE 1 In a pot having a diameter of 15 cm, tobacco (var: Bright yellow) was cultured. When the tobacco had grown to a height of about 40 cm and had grown 7 8 nodes, the tobacco was topped. An aqueous dispersion containing 1000 ppm of an active ingredient was sprayed on the stems and leaves of the tobacco plants in quantities of 20 ml per plant. After 20 days from the date of application of the spray, the suckers were removed from the plants and collected. The weight of the fresh suckers was measured, and the extent of chemical injury to the leaves was observed. The percent sucker inhibition was calculated by the following equation.

weight of fresh sucker per plant in the treated pot weight of fresh sucker per plant in the untreated pot sucker inhibition l X Table l Com- Active ingredient poun No. Sucker Chemical Inhibition Injury l benzyl N,N-di-n-propylthiolcarbamate 100 none 2 2-methylbenzyl-N,N-di-npropylthiolcarbamate 100 none (b.p. l58-l62C/2 r'nmHg) 3 3-methylbenzyl-N,N-di-npropylthiolcarbamate 100 none (b.p. l54156C/l.5 mmHg) 4 4-methylbenzyl-N,N-di-npropylthiolcarbamate 100 none (b.p. 147l49C/l mmHg) 5 2-chlorobenzyl-N,N-di-npropylthiolcarbamate 100 none (b.p. l62-165C/2 mmHg) 6 4-chlorobenzyl-N,N-di-npropylthiolcarbamate 100 none (b.p. 163166C/l.5 mmHg) 7 2-fluorobenzyl-N,Ndi-npropylthiolcarbamate 100 none (b.p. l54l58C/2 mmHg) 8 4fluorobenzyl-N,N-di-npropylthiolcarbamate 100 none (b.p. l55l60C/2 mmHg) 9 Z-methyl-S-chlorobenzyl- N,N-di-n-propylthiolcarbamate 100 none 10 2-methoxy-5-chlorobenzyl- N ,N-di-n-propylthiolcarbamate 100 none 1 l 2-methyl-3-bromobenzyl- N,N-di-n-propylthiolcarbamate 100 none 12 4nitrobenzylN,N-di-npropylthiolcarbamate 100 none 13 2-methyl-5-nitrobenzyl N,N

di-n-propylthiolcarbamate 100 none 14 4-aminobenzyl-N,N-di-npropylthiclcarbamate l 00 none 15 2,5-dichlorobenzyl-N,N-din-propylthiolcarbamate 100 none 16 2,4-dimethylbenzyl-N,N-din-propylthiolcarbamate 100 none Table I-Continued Com- Active ingredient pound No. Sucker Chemical Inhibition Injury l7 3-chloro-4-methylbenzyl-N,N-

di-n-propylthiolcarbamate 100 none 1 8 2-methoxy-5-bromobcnzyl- N ,N-di-n-propylthiolcarbamate I00 none 19 2-ethoxy-5-chlorobenzyl-N,N-

di-n-propylthiolcarbamate 100 none 20 3-acetylbenzyl N,N-din-propylthiolcarbamate 100 none 2l 2-ethoxybenzyl'N,N-

dimethylthiolcarbamate 100 none 22 2,5-dimethoxybenzyl-N,N-

dim ethylthiolcarbamate 100 none 23 2-methoxy-5-chlorobenzyl- N,N-dimethylthiolcarbamate l 00 small 24 2-ethylbenzyl-N,N-diethylthiolcarbamate 100 none 25 benzyl N,N-diethylthiolcarbamatc 100 none 26 4-chlorobenzyl-N,N-

d iethylthiolcarbam ate 100 none 27 benzyl N,N-di-nbutylthiolcarbamate 100 none 28 2-chlorobenzyl-N,N-di-nbutylthiolcarbamate 100 none 29 4-methylbenzyl-N,N-di'nbutylthiolcarbam ate 100 none 30 2-methyl-5-chlorobenzyl N,N-di-iso-propylthiolcarbamate l00 none 3] 4-fluorobenzyl-N,N-di-isopropylthiolcarbamate l00 none 32 4-chlorobenzyl N-methyl- Nac etylthiolcarb amate 100 none 33 benzyl-N-ethyl-N-acetylthiolcarbamate l 00 none 34 4-chlorobenzyl-N-ethyl-N- acetylthiolearbamate 100 none 35 benzyl-N-ethyl-N- cyclohexylthiolcarbamate 100 none 36 2,5-dichlorobenzyl-N-ethyl- N-cyclohexylthiolcarbamate 100 none 37 benzyl-N-methyl-N- cyclohexylthiolcarbamate 100 none 38 4-chlorobenzyl-N-methyl-N- cyclohexylthiolcarbamate I00 none 39 2,5-dichlorobenzyl-N- methyl-N-cyclohexylthiolcarbamate 100 none 40 Z-methylbenzyl-N-methyl- N-cyclohexylthiolcarbamate 100 none 41 4-methylbenzyl-N-methyl- N-cyclohexylthiolcarbamate I00 none Cont. l none 0 none EXAMPLE 2 In accordance with the method of Experiment 1 further tobacco sucker inhibition tests were conducted except that the concentration of the active ingredients in the solutions applied to the plants was 250, 500 and 2000 ppm. The results of the example are shown in Table II.

Table II-Continued Test Active ingredient Concent- No. ration sucker Chemical (ppm) inhibition Injury 500 I00 250 2 5 Compound 5 2,000 I00 none 500 100 250 100 2 6 Compound 6 2,000 100 none 500 I00 250 I00 2 7 Compound 7 2,000 I00 none 500 I00 250 100 2 8 Compound 8 2,000 100 none 500 I00 250 I00 2 9 Compound 9 2,000 I00 small 500 I00 none 250 I00 Control l 0 none EXAMPLE 3 In a pot having a diameter of 15 cm, a tobacco (var: Bright yellow) was cultured. When the tobacco had grown to a height of about 1 m when 20 25 nodes had grown, and when from 1 2 flower buds had bloomed, the tobacco was topped. When the suckers had grown to a length of to 2 3 cm after 7 days from topping, various concentrations of each active ingredient in aqueous dispersions were sprayed onto the stems and leaves of tobacco plants in quantities of 20 ml per plant.

In a comparative test (Control-2), a 58 percent aqueous dispersion of the diethanolamine salt of maleic hydrazide was sprayed onto the stems and leaves of tobacco plants. Twenty days after the day of application, the percent of sucker inhibition and the extent of chemical injury were measured in accordance with the method of Experiment 1. The results are shown in Table III. The concentration of Test Nos. 3-10 is in terms of maleic hydrazide in Table III.

Table III Test Active ingredient Concen- Chemical No. tration sucker injury inhibition (pp 3 1 Compound 1 4,000 100 none 2,000 100 1,000 100 500 100 3 2 Compound 2 4,000 100 none 2,000 100 1,000 I00 500 100 3 3 Compound 3 4,000 100 small 2,000 100 small 1,000 100 none 500 100 3 4 Compound 4 4,000 100 none 2,000 100 1,000 100 500 I00 3 5 Compound 5 4,000 l00 none 2,000 100 L000 100 500 100 3 6 Compound 6 4,000 100 none 2,000 100 1,000 100 500 100 3 7 Compound 7 4,000 100 none 2,000 100 1,000 l00 500 I00 3 8 Compound 8 4,000 100 none In a pot of 1/2000 are (1/81000 acre) on a wet field, tobacco (var: Bright yellow) was cultured. When the tobacco had grown to a height of about 1 m, and when the flower buds had just begun to bloom, the tobacco was topped. This tobacco was used for the tests. The tobacco was planted in quantities of 1 plant per pot, and the tests were conducted twice. The active ingredients and the auxiliary active ingredients were formulated as follows:

1. Active ingredient N,N-dialky1benzylthiolcarbamate: a. 20 parts by weight N,N-dialkylbenzylthiolcarbamate b. 70 parts by weight xylene, and

c. 10 parts by weight polyoxyethylene laurylether were mixed and the mixture was emulsified for each of the desired concentration;

2. Auxiliary active ingredient: an alkyl-N- phenylcarbamate or a 4-substituted aniline derivative.

An emulsion of the auxiliary active ingredient was prepared in accordance with the method shown above except that N,N-dialkylbenzylthiolcarbamate was replaced with an alkyl-N-phenylcarbamate or a 2,6-dinitro-4-substituted aniline derivative.

In order to test the differences in effectiveness between the active ingredients of this invention, and especially the special effectiveness of the compositions containing the active ingredient and the auxiliary active ingredient, the sucker inhibition percentage was measured days after the date of application of sprays containing the compositions indicated. The results are shown in Tables IV X.

Table IV Test Active Auxiliary active No. ingredient concentingredient concent- Sucker ration ration inhibition (pp (pp Control 1 0 0 0 Control 2 maleic hydrazide 4000 2000 63 I000 25 4 0 0 lsopropyl-N- 4000 69 (3-chlorophenyl) 2000 53 carbamate 1000 41 4 1 Compound 1 4,000 0 75 2,000 1000 1,000 1000 100 500 1000 100 4 2 Compound 2 4,000 0 84 2,000 1000 100 1,000 1000 100 500 I000 100 4 3 Compound 3 4,000 0 81 2,000 1000 100 1,000 1000 100 500 1000 100 4 4 Compound 4 4,000 0 73 I 2,000 1000 100 1,000 1000 100 500 1000 100 4 5 Compound 5 4,000 0 82 2,000- 1000 100 1,000 1000 100 500 1000 100 4 6 Compound 6 4,000 0 84 2,000 1000 100 1,000 1000 100 500 1000 100 4 7 Compound 7 4,000 0 78 2,000 1000 100 1,000 1000 100 v500 1000 100 4 8 Compound 8 4,000 0 i 77 2,000 1000 100 1,000 1000 100 500 1000 100 Table V Test Active Auxiliary active N0. ingredient Coneentingredient Concentsucker ration ration inhibition (pp (PP 5 0 lsopropyl N 4,000 46 phenylearbamate 2,000 31 1,000 18 1 Compound 1 2,000 1,000 100 1,000 1,000 100 500 1,000 91 5 2 Compound 2 2,000 1,000 100 1,000 1,000 100 500 1,000 94 5 3 Compound 3 2,000 1,000 100 1,000 1,000 100 500 1,000 88 5 4 Compound 4 2,000 1,000 98 1,000 1,000 94 500 1,000 72 5 5 Compound 5 2,000 1,000 100 l ,000 l .000 100 500 1,000 92 5 6 Compound 6 2,000 1,000 100 1 ,000 1,000 92 500 1,000 5 7 Compound 7 2,000 1,000 100 1,000 1,000 100 500 1.000 5 8 Compound 8 2,000 1,000 93 1,000 1,000 87 500 1,000 75 Table VI Test Active Auxiliary active No. ingredient Concentingredient Concentsucker ration ration inhibition p (pp 6 0 lsopropyl N- 4,000 72 (3-methylphenyl) 2,000 56 0 carbamate 1,000 43 6 1 Compound 1 2,000 1,000 100 1 ,000 1,000 100 500 1,000 96 6 2 Compound 2 2,000 L000 [00 1,000 1,000 100 500 1,000 100 6 3 Compound 3 2,000 1,000 100 1,000 1,000 100 500 1,000 100 6 4 Compound 4 2,000 1,000 100 1,000 1,000 100 500 1,000 6 5 Compound 5 2,000 1,000 1,000 1,000 100 500 1.000 100 6 6 Compound 6 2,000 1,000 100 1,000 1,000 100 500 1,000 100 6 7 Compound 7 2,000 1,000 100 l ,000 1,000 100 500 1,000 l00 6 8 Compound 8 2,000 1,000 100 1,000 1,000 100 500 1,000 89 Table Vll Test Active Auxiliary active No. ingredient Conceningredient Coneentsucker tration trution inhibition (ppm) (ppm) 7 O sec-hutyl N- 4,000 66 (3-methylphenyl) 2,000 44 0 curb-amine 1,000 28 7 1 Compound I 2,000 1,000 100 l ,000 l .000 100 500 1,000 98 7 2 Compound 2 2,000 1,000 100 1,000 1,000 100 500 1,000 98 7 3 Compound 3 2,000 1,000 100 l ,000 1,000 100 500 1,000 92 7 4 Compound 4 2,000 1,000 100 l ,000 1,000 100 500 1,000 88 Table V11 Continued Test Active Auxiliary active No ingredient Cnccningredient Conccnt sucker [ration tration inhibition (pp (pp 0% 7 Compound 5 2,000 1,000 100 1,000 1,000 100 500 1,000 96 7 6 Compound 6 2,000 1,000 100 1,000 1,000 96 500 1,000 97. 7 7 Compound 7 2,000 1,000 100 1,000 1,000 100 500 1,000 89 7 8 Compound 8 2,000 1,000 100 1,000 1,000 91 500 1.000 87 Table VIII Test Active Auxiliary active No. ingredient Conceningredient Concensucker tration tration inhibition (PP (pp 8 0 N-sec-buty1-4- 0 tert-butyl 4,000 68 2,6-dinitro- 2,000 56 aniline 1,000 5 2 8 1 Compound 1 2,000 1,000 100 1,000 1,000 100 500 1,000 100 8 2 Compound 2 2,000 1,000 100 1 ,000 1,000 100 500 1,000 100 8 3 Compound 3 2,000 1,000 100 1,000 1,000 100 500 1,000 100 8 4 Compound 4 2,000 1,000 100 1,000 1,000 100 500 1,000 98 8 5 Compound 5 2,000 1,000 100 1,000 1,000 100 500 1,000 100 8 6 Compound 6 2,000 1,000 100 1,000 1,000 100 500 1,000 100 8 7 Compound 7 2,000 1,000 100 1,000 1,000 100 500 1,000 100 8 8 Compound 8 2,000 1,000 100 1,000 1,000 100 500 1,000 100 Table IX Test Active Auxiliary active No. ingredient Concentingredient Concentsucker ration ration inhibition (ppm) (pp 9 0 N,Ndi-n-propyl 4-trifluoromethyl 4,000 52 2,6-dinitro- 2,000 31 aniline 1,000 1 l 9 1 Compound 1 2,000 1,000 100 1,000 1,000 88 500 1,000 9 2 Compound 2 2,000 1,000 100 1,000 1.000 500 1.000 86 9 3 Compound 3 2,000 1,000 1 ,000 l .000 86 500 1,000 74 9 4 Compound 4 2,000 1,000 100 1,000 1,000 75 500 1,000 60 9 5 Compound 5 2.000 1,000 100 l ,000 1,000 92 500 1,000 84 9 6 Compound 6 2,000 1,000 100 1 ,000 1,000 85 500 1.000 71 9 7 Compound 7 2,001) 1,000 100 1 ,000 1 ,000 85 500 1,000 76 I 9 8 Compound 8 2.000 1,000 92 1,000 1,000 88 500 1,000 72 Table X Test Active Auxiliary activc No. ingredient Concentingredient Concentsucker ration ration inhibition (pp (pp l 0 N,Ndi-n-propyl 4-methylsulfonyl 4,000 49 2,6-dinitro- 2,000 26 aniline 1,000 l2 l0 1 Compound 1 2,000 1,000 96 1,000 1,000 88 500 1,000 66 10 2 Compound 2 2,000 1,000 92 1,000 1,000 78 500 1,000 72 10 3 Compound 3 2,000 1,000 91 1,000 1,000 76 500 1,000 60 10 4 Compound 4 2,000 1,000 96 500 1,000 71 10 5 Compound 5 2,000 1,000 91 l ,000 1,000 77 500 1,000 71 6 Compound 6 2,000 1,000 100 1,000 1,000 82 500 1,000 65 10 7 Compound 7 2,000 1,000 90 1,000 L000 82 500 1,000 79 10 8 Compound 8 2,000 1,000 88 1,000 1,000 72 500 1,000 61 According to the test results, the active benzylthiolcarbamate ingredients of this invention exhibit a remarkable inhibitory effect on the growth of tobacco suckers compared to other sucker inhibitors such as maleic hydrazide. At the same time very little chemical injury is observed on the treated tobacco leaves.

In the instances when an auxiliary active ingredient such as an alkyl N-phenylcarbamate or a 2,6-dinitro-4- substituted aniline derivative was blended with an N,N- dialkylbenzylthiolcarbamate for the treatment of tobacco suckers, the blend of ingredients exhibited a remarkable synergistic effect in the treatment of the plants. Inhibition of tobacco sucker for those plants treated with this blend was maintained for a substantially longer period of time than for those plants treated with a single active ingredient or maleic hydrazide.

Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto with out departing from the spirit or scope of the invention as set forth herein.

What is claimed as new and desired to be secured by (X) ECW129101 (Yl wherein R and R are selected from the group consisting of 65 acetyl, cyclohexyl, and C alkyl groups:

5 ing from 1 ml.

3. The method of claim 1, wherein said benzylthiolcarbamate is applied while the tobacco plants are in the topping stage.

4. The method of claim 1, wherein said benzylthiol- 0 carbamate is N,N-dialkylbenzylthiolcarbamate having the formula CHZSCN wherein R and R represent C alkyl groups and Z is selected from the group consisting of hydrogen, methyl, chlorine, and fluorine. 5. The method of claim 1, wherein said benzylthiolcarbamate is selected from the group consisting of 2 methylbenzyl N,N-di-n-propylthiolcarbamate, S-methylbenzyl N,Ndi-n-propylthiolcarbamate, 4=methylbenzyl N,N-di-n-propylthiolcarbamate, Z-ehlorobenzyl N,N-di-n-propylthiolcarbamate, 4=chlorobenzyl N,N-di-n-propylthiolcarbamate, 2-tluorobenzyl N,N-di-n-propylthiolcarbamate, and 4 fluorobenzyl N,N-di-n propylthiolcarbamatei i l =l a 

1. A METHOD OF INHIBITING THE GROWTH OF SUCKERS OF TOBACCO PLANTS WHICH COMPRISES APPLYING TO TOBACCO PLANT, AN EFFECTIVE AMOUNT BENZYLTHIOLCARBAMATE HAVING THE FORMULA,
 2. The method of claim 1, wherein said benzylthiolcarbamate is applied to each tobacco plant in the concentration range of 100 -10,000 ppm in amounts ranging from 1 - 100 ml.
 3. The method of claim 1, wherein said benzylthiolcarbamate is applied while the tobacco plants are in the topping stage.
 4. The method of claim 1, wherein said benzylthiolcarbamate is N,N-dialkylbenzylthiolcarbamate having the formula
 5. The method of claim 1, wherein said benzylthiolcarbamate is selected from the group consisting of 2-methylbenzyl N,N-di-n-propylthiolcarbamate, 3-methylbenzyl N,N-di-n-propylthiolcarbamate, 4-methylbenzyl N,N-di-n-propylthiolcarbamate, 2-chlorobenzyl N,N-di-n-propylthiolcarbamate, 4-chlorobenzyl N,N-di-n-propylthiolcarbamate, 2-fluorobenzyl N,N-di-n-propylthiolcarbamate, and 4-fluorobenzyl N,N-di-n-propylthiolcarbamate. 